Electromagnets and Their Uses

Active learning builds deep understanding of electromagnetism by letting students feel the pull of magnetic fields with their own hands. When 8th graders wrap wire, connect batteries, and lift paper clips, they see cause and effect in real time. This hands-on work makes abstract ideas—like how current creates a field—tangible and unforgettable.

• 8th Grade
• Science
• 3 activities
• 30 min–55 min

Learning Objectives

1. Explain how the movement of electric charges creates a magnetic field.
2. Analyze the relationship between the number of wire coils, the current, and the strength of an electromagnet.
3. Design and construct a simple electromagnet to perform a specific task, such as picking up a target number of paper clips.
4. Compare the magnetic field strength of electromagnets with varying core materials.

Project-Based Learning

⏱ 50 min·Small Groups

Lab Investigation: Building and Testing an Electromagnet

Student groups wrap varying numbers of coils of insulated wire around an iron nail and connect it to a battery. They count how many paper clips each configuration picks up, systematically varying coil number while keeping current constant, then voltage while keeping coil number constant. Groups share results on a class data table and draw conclusions about each variable.

Prepare & details

Explain how an electric current can create a magnetic field.

Facilitation Tip: During Lab Investigation, have students record coil count, battery count, and paper clip pickup in a shared class chart so everyone sees how variables connect.

Setup: Flexible workspace with access to materials and technology

Materials: Project brief with driving question, Planning template and timeline, Rubric with milestones, Presentation materials

• Apply
• Analyze
• Evaluate
• Create
• Self-Management
• Relationship Skills
• Decision-Making

Project-Based Learning

⏱ 55 min·Small Groups

Engineering Design Challenge: Electromagnet for a Purpose

Each group receives a design brief: build the strongest electromagnet possible from given materials, or build one that can be switched on and off remotely, or build one that lifts exactly 10 paper clips (not more, not fewer). Groups plan, build, test, and present their design rationale and results to the class.

Prepare & details

Analyze the factors that affect the strength of an electromagnet.

Facilitation Tip: For the Engineering Design Challenge, set a clear weight goal (e.g., lift 50 paper clips) to focus the build and make testing consistent across teams.

Setup: Flexible workspace with access to materials and technology

Materials: Project brief with driving question, Planning template and timeline, Rubric with milestones, Presentation materials

• Apply
• Analyze
• Evaluate
• Create
• Self-Management
• Relationship Skills
• Decision-Making

Gallery Walk

⏱ 30 min·Pairs

Gallery Walk: Electromagnet Applications

Post images and brief descriptions of six electromagnetic technologies (electric motor, MRI scanner, maglev train, electric guitar pickup, hard disk, junkyard crane). Pairs visit each station, identify which factors (coil count, current, core material) are engineered for each application, and explain why. The class shares the most interesting engineering decision from each station.

Prepare & details

Design an electromagnet for a specific application.

Facilitation Tip: During the Gallery Walk, post application photos with brief captions so students focus on how electromagnet design matches function in real devices.

Setup: Wall space or tables arranged around room perimeter

Materials: Large paper/poster boards, Markers, Sticky notes for feedback

• Understand
• Apply
• Analyze
• Create
• Relationship Skills
• Social Awareness

Teaching This Topic

Teachers should emphasize variable control in the lab—only change one factor at a time—so students learn scientific method alongside physics. Avoid rushing to conclusions; let failed builds (like melted wire) become teaching moments about limits of current and heat. Research shows that when students graph their data, they better grasp proportional relationships between coils and strength.

What to Expect

Students will connect the number of coils, battery voltage, and core material to the strength of their electromagnet. They will explain why an electromagnet can be turned on and off, and describe at least two real-world uses based on its adjustable power. Clear labeling and measured data in their lab notes will show their grasp of variables and results.

Watch Out for These Misconceptions

Common Misconception

During Lab Investigation: Watch for students who treat their electromagnet like a permanent magnet and expect it to stay on or lift objects without a battery connection.

What to Teach Instead

Have students deliberately disconnect the battery to see the electromagnet turn off immediately—this concrete action shows the on/off control that permanent magnets lack.

Common Misconception

During Lab Investigation: Watch for teams who stack multiple batteries hoping for unlimited strength.

What to Teach Instead

Ask students to feel the wire after testing and connect heat to reduced performance—this links engineering limits to physical science in a memorable way.

Common Misconception

During Lab Investigation: Watch for students who assume only iron nails work as cores.

What to Teach Instead

Provide a plastic pen core and an empty coil setup so students test all three options and rank their strengths based on paper clip pickup data.

Assessment Ideas

Quick Check

After Lab Investigation, present the three electromagnets with different coil counts and ask students to predict the strongest one. Then have them test by counting paper clips and explain why the results matched or differed from their predictions.

Discussion Prompt

During Engineering Design Challenge, pose the question: ‘What factors would you adjust to make your electromagnet strong enough to sort iron ore?’ Guide students to discuss coil number, current, and core material based on their lab findings.

Exit Ticket

After Lab Investigation, ask students to draw a simple electromagnet and label the parts that affect strength. Then have them write one sentence explaining how increasing the current would change the electromagnet's power.

Extensions & Scaffolding

• Challenge: Ask students to design a dual-coil electromagnet to see if two smaller coils side-by-side produce stronger or weaker fields than one continuous coil.
• Scaffolding: Provide a data table with blanks for coil count and paper clip count to support students who struggle with setup or recording.
• Deeper exploration: Have students research how MRI machines use superconducting electromagnets and compare their design to their classroom models.

Key Vocabulary

Electromagnetism	The interaction of electric currents or fields and magnetic fields. It is the basis for how electromagnets work.
Electromagnet	A temporary magnet created when an electric current flows through a wire coiled around a ferromagnetic core, like iron.
Magnetic Field	The region around a magnetic material or a moving electric charge within which the force of magnetism acts.
Ferromagnetic Core	A material, such as iron, that is strongly attracted to magnets and can be magnetized itself, significantly increasing the strength of an electromagnet.